Method of obtaining hydrogen concentration in hydrogen-containing liquid and generator for hydrogen-containing liquid

ABSTRACT

The generator comprises: a hydrogen supply source ( 2 ) configured to continuously supply a hydrogen-containing gas; a liquid supply source ( 3 ) configured to continuously supply a liquid; a dissolving unit ( 4 ) configured to dissolve the hydrogen-containing gas in the liquid; a memory ( 5 ) configured to store preliminarily-obtained relational information among a flow rate, water pressure, and hydrogen concentration of the hydrogen-containing liquid passing through the dissolving unit; a flow rate detector ( 52 ) configured to detect the flow rate of the hydrogen-containing liquid; a water pressure detector ( 51 ) configured to detect the water pressure of the hydrogen-containing liquid; and a calculator ( 5 ) configured to obtain the hydrogen concentration on the basis of the detected flow rate and water pressure and the relational information.

TECHNICAL FIELD

The present invention relates to a method of obtaining a hydrogen concentration in a hydrogen-containing liquid and relates also to a generator for a hydrogen-containing liquid.

BACKGROUND ART

For use in an electrolyzed water generator that generates electrolyzed water, a method of measuring a dissolved hydrogen concentration in the generated hydrogen water is known (Patent Document 1: JP2015-087221A). This method includes a measurement step and a calculation step. The measurement step is designed to measure current flowing between a cathode plate disposed in a cathode chamber and an anode plate disposed in an anode chamber and to measure a discharge flow rate of the hydrogen water generated in the cathode chamber. The calculation step is designed to calculate a dissolved hydrogen concentration in the hydrogen water generated in the cathode chamber in accordance with the current and discharge flow rate measured in the measurement step, on the basis of data that represents a correlation between the preliminarily measured current and discharge flow rate and the dissolved hydrogen concentration in the hydrogen water.

PRIOR ART DOCUMENT Patent Document

-   [Patent Document 1] JP2015-087221A

SUMMARY OF INVENTION Problems to be Solved by Invention

The dissolved hydrogen concentration in the above prior art electrolyzed water is less than 1 ppm (see FIGS. 1, 2, 6, and 7 of the document), which may be insufficient to exhibit antioxidative properties.

Problems to be solved by the present invention include providing a method of obtaining a hydrogen concentration even in a high-concentration hydrogen-containing liquid and providing a generator for a hydrogen-containing liquid.

Means for Solving Problems

The present invention solves the above problems through preliminarily obtaining a relationship among a flow rate, water pressure, and hydrogen concentration of a hydrogen-containing liquid, detecting the flow rate and water pressure of the hydrogen-containing liquid, and obtaining the hydrogen concentration on the basis of the detected flow rate and water pressure and the preliminarily-obtained relationship.

According to another aspect, the present invention solves the above problems through preliminarily obtaining a relationship among an electric quantity during electrolysis, a water pressure of a hydrogen-containing liquid, and a hydrogen concentration, detecting the electric quantity during the electrolysis and the water pressure of the hydrogen-containing liquid, and obtaining the hydrogen concentration on the basis of the detected electric quantity and water pressure and the preliminarily-obtained relationship.

Effect of Invention

According to the present invention, the hydrogen concentration can be obtained even in a high-concentration hydrogen-containing liquid.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating an embodiment of the generator for a hydrogen-containing liquid according to the present invention.

FIG. 2 is a block diagram illustrating another embodiment of the generator for a hydrogen-containing liquid according to the present invention.

FIG. 3 is a block diagram illustrating still another embodiment of the generator for a hydrogen-containing liquid according to the present invention.

FIG. 4 is a block diagram illustrating yet another embodiment of the generator for a hydrogen-containing liquid according to the present invention.

MODE(S) FOR CARRYING OUT THE INVENTION

FIG. 1 is a block diagram illustrating an embodiment of a generator 1 for generating a hydrogen-containing liquid according to the present invention. As illustrated in the figure, the generator 1 of the present embodiment comprises a hydrogen supply source 2 configured to supply a hydrogen-containing gas, a liquid supply source 3 configured to supply a liquid, and a dissolving unit 4 configured to dissolve the hydrogen-containing gas in the liquid.

The hydrogen supply source 2 is to supply a gas that contains a hydrogen component as the primary component (referred also to as a “hydrogen-containing gas,” hereinafter). Examples of the hydrogen supply source 2 include a hydrogen gas cylinder, hydrogen storing alloy, fuel reformer, and electrolyzed water generator. The hydrogen-containing gas supplied from the hydrogen supply source 2 is sent to a junction part 41 via a hydrogen supply tube 21. The hydrogen supply tube 21 is provided with a check valve 22, and the hydrogen-containing gas having passed through the check valve 22 does not return to the hydrogen supply source 2. The hydrogen supply tube 21 may be provided with a fluid pressurization pump to regulate the supply pressure of the hydrogen-containing gas from the hydrogen supply source 2 to the junction part 41.

The liquid supply source 3 is to supply a liquid of the intended hydrogen-containing liquid, that is, a liquid to which hydrogen gas is to be dissolved. Examples of the liquid include water such as tap water, beverage, and medicinal liquid. The liquid supplied from the liquid supply source 3 is sent to the junction part 41 via a liquid supply tube 31. The liquid supply tube 31 may be provided with a fluid pressurization pump to regulate the supply pressure of the liquid from the liquid supply source 3 to the junction part 41. The liquid supply tube 31 may also be provided with a check valve so that the liquid from the liquid supply source 3 does not return thereto.

The junction part 41 is composed of a piping joint that connects between the hydrogen supply tube 21 and the liquid supply tube 31. The hydrogen-containing gas and liquid reaching the junction part 41 flow into a gas/liquid mixing pipe 42 and are sent under pressure to the downstream side by a fluid pressurization pump 43 provided at the gas/liquid mixing pipe 42. The gas/liquid mixing pipe 42 is provided with a dissolving unit 4 at the downstream side from the fluid pressurization pump 43. The gas/liquid mixing pipe 42 is also provided with a flow rate regulating valve 44 at the downstream side from the dissolving unit 4.

The dissolving unit 4 is a cylindrical body having a larger inner diameter than that of the gas/liquid mixing pipe 42 and comprises a mixing body having fine pores, such as a membrane filter, which is provided inside the cylindrical body. When the gas/liquid mixture of the hydrogen-containing gas and the liquid passes through the fine pores of the membrane filter or the like, the hydrogen-containing gas becomes fine bubbles thereby to increase their surface area in contact with the liquid. Moreover, the hydrogen concentration increases because the hydrogen-containing gas in a form of fine bubbles and the liquid are pressurized in accordance with the pressurizing force by the fluid pressurization pump 43 and the opening degree of the flow rate regulating valve 44. The hydrogen-containing liquid, which thus has a high concentration, is supplied from a supply port 45 to an intended site.

The generator 1 for generating a hydrogen-containing liquid according to the present embodiment comprises, in addition to the above-described configuration, a water pressure detector 51 configured to detect the water pressure of the hydrogen-containing liquid, a flow rate detector 52 configured to detect the flow rate of the hydrogen-containing liquid, a calculator 5, and a display 6.

The water pressure detector 51 is provided on the gas/liquid mixing pipe 42 between the fluid pressurization pump 43 and the dissolving unit 4 and detects the water pressure of the hydrogen-containing liquid (gas/liquid mixture of the hydrogen-containing gas and the liquid) which is pressurized by the fluid pressurization pump 43. The detection signal from the water pressure detector 51 is read out by the calculator 5 at a predetermined time interval. In an alternative embodiment, the water pressure detector 51 may be provided on the gas/liquid mixing pipe 42 between the dissolving unit 4 and the flow rate regulating valve 44.

The flow rate detector 52 detects the opening degree of the flow rate regulating valve 44 to detect the flow rate of the hydrogen-containing liquid. The detection signal from the flow rate detector 52 is read out by the calculator 5 at a predetermined time interval. In an alternative embodiment, the flow rate detector 52 may be provided on the gas/liquid mixing pipe 42 between the flow rate regulating valve 44 and the supply port 45.

The calculator 5 is composed of a microcomputer that includes a CPU, ROM, and RAM. The ROM also functions as a storage that stores preliminarily-obtained relational information among the flow rate, water pressure, and hydrogen concentration of the hydrogen-containing liquid passing through the dissolving unit 4. In the ROM, a calculation program is established to obtain the hydrogen concentration in actual use on the basis of the detected flow rate and water pressure and the relational information.

The display 6 is to present the hydrogen concentration obtained by the calculator 5. Examples of the display 6 include indicators, such as a seven-segment digital indicator, with which the concentration can be visually recognized and those, such as a speaker, with which the concentration can be audibly perceived.

The generator 1 for generating a hydrogen-containing liquid as illustrated in FIG. 1 was made using a three-layer electrolytic cell available from MiZ Company Limited as the hydrogen supply source 2, tap water as the liquid supply source 3, CDP8800 available from Aquatec as the fluid pressurization pump 43, and MOM-PF5 (membrane filter) available from MonotaRO Co., Ltd. as the dissolving unit 4. The flow rate of the hydrogen-containing gas supplied from the hydrogen supply source 2 to the junction part 41 was controlled by a value of current flowing through electrodes of the MiZ three-layer electrolytic cell. The flow rate of the tap water supplied from the liquid supply source 3 to the junction part 41 was controlled by the opening degree of the water outlet. The pressure of the gas/liquid mixture between the fluid pressurization pump 43 and the dissolving unit 4 was controlled by the fluid pressurization pump 43 and the flow rate regulating valve 44. The dissolved hydrogen concentration was measured (titrated) with a dissolved hydrogen concentration measuring reagent (9.88 ml of alcohols containing ethanol, methylene blue, and colloidal platinum) available from MiZ Company Limited using a dropper for dropping the reagent drop by drop, one drop capable of reacting with 0.1 ppm of hydrogen. This titration was performed by counting the number of drops when the blue reagent turned to transparent. Results are listed in Table 1.

TABLE 1 Correlation coefficient between Hydrogen pressure and Flow rate Pressure concentration hydrogen Deaeration Current (A) (L/min) (MPa) (ppm) concentration Example 1 None 18.0 3.0 0.4 2.2 0.983 Example 2 18.0 3.0 0.3 2.0 Example 3 18.0 3.0 0.2 1.8 Example 4 18.0 3.0 0.1 1.4 Example 5 None 18.0 1.5 0.4 2.5 0.988 Example 6 18.0 1.5 0.3 1.9 Example 7 18.0 1.5 0.2 1.5 Example 8 18.0 1.5 0.1 1.2 Example 9 None 6.0 1.5 0.4 1.3 0.976 Example 10 6.0 1.5 0.3 1.0 Example 11 6.0 1.5 0.2 0.8 Example 12 6.0 1.5 0.1 0.7

Examples 1 to 4 are those in which the hydrogen concentration was measured when the flow rate of the hydrogen-containing gas from the hydrogen supply source 2 was constant (18.0 A), the flow rate of the tap water from the liquid supply source 3 was constant (3.0 L/min), and the pressure of the gas/liquid mixture was varied from 0.1 to 0.4 MPa. The correlation coefficient between the pressure of the gas/liquid mixture and the hydrogen concentration is 0.983, which is very close to 1. Examples 5 to 8 are those in which the hydrogen concentration was measured when the flow rate of the tap water was 1.5 L/min as substitute for 3.0 L/min in Examples 1 to 4 and the pressure of the gas/liquid mixture was varied from 0.1 to 0.4 MPa. The correlation coefficient between the pressure of the gas/liquid mixture and the hydrogen concentration is 0.988, which is very close to 1. Examples 9 to 12 are those in which the hydrogen concentration was measured when the flow rate of the hydrogen-containing gas was 6.0 A as substitute for 18.0 A in Examples 5 to 8 and the pressure of the gas/liquid mixture was varied from 0.1 to 0.4 MPa. The correlation coefficient between the pressure of the gas/liquid mixture and the hydrogen concentration is 0.976, which is very close to 1.

As the above, the correlation coefficient between the pressure of the gas/liquid mixture and the hydrogen concentration is very close to 1 at a given flow rate of the hydrogen-containing gas from the hydrogen supply source 2 and a given flow rate of the tap water from the liquid supply source 3. Accordingly, a relational expression thereamong is preliminarily obtained and stored in the ROM of the calculator 5. When the generator 1 for generating a hydrogen-containing liquid is actually used with a fixed value of the flow rate of the hydrogen-containing gas from the hydrogen supply source 2, that is, a fixed value of the current, the flow rate detected by the flow rate detector 52 and the water pressure detected by the water pressure detector 51 are read into the calculator 5, and the detected flow rate and the detected pressure are substituted into the relational expression to obtain the hydrogen concentration using the calculation program established in the ROM for obtaining the hydrogen concentration. This obtained hydrogen concentration is presented by the display 6 and the user can thus perceive the hydrogen concentration in the hydrogen-containing liquid from the supply port 45.

FIG. 2 is a block diagram illustrating another embodiment of a generator 1 for generating a hydrogen-containing liquid according to the present invention. As illustrated in the figure, the generator 1 of the present embodiment is different from the generator 1 illustrated in FIG. 1 in that the liquid supply tube 31 is provided with a deaeration module 32 and a vacuum pump 33, and other features are the same as those illustrated in FIG. 1. Turning on the vacuum pump 33 to operate the deaeration module 32 allows gases (mainly oxygen and other gases) to be removed (namely, to be deaired) from the liquid supplied from the liquid supply source 3. This operation can enhance the hydrogen concentration because the amount of contact between the liquid and the hydrogen gas increases in the pass from the junction part 41 to the dissolving unit 4.

The generator 1 for generating a hydrogen-containing liquid as illustrated in FIG. 2 was made using a three-layer electrolytic cell available from MiZ Company Limited as the hydrogen supply source 2, tap water as the liquid supply source 3, SEPAREL EF-002A-P available from DIC Corporation as the deaeration module 32, DAP-6D available from ULVAC, Inc. as the vacuum pump 33 for the deaeration module 32, CDP8800 available from Aquatec as the fluid pressurization pump 43, and MOM-PF5 (membrane filter) available from MonotaRO Co., Ltd. as the dissolving unit 4. The flow rate of the hydrogen-containing gas supplied from the hydrogen supply source 2 to the junction part 41 was controlled by a value of current flowing through electrodes of the MiZ three-layer electrolytic cell. The flow rate of the tap water supplied from the liquid supply source 3 to the junction part 41 was controlled by the opening degree of the water outlet. The pressure of the gas/liquid mixture between the fluid pressurization pump 43 and the dissolving unit 4 was controlled by the fluid pressurization pump 43 and the flow rate regulating valve 44. The dissolved hydrogen concentration was measured (titrated) with a dissolved hydrogen concentration measuring reagent (9.88 ml of alcohols containing ethanol, methylene blue, and colloidal platinum) available from MiZ Company Limited using a dropper for dropping the reagent drop by drop, one drop capable of reacting with 0.1 ppm of hydrogen. This titration was performed by counting the number of drops when the blue reagent turned to transparent. Results are listed in Table 2.

TABLE 2 Correlation coefficient between Hydrogen pressure and Flow rate Pressure concentration hydrogen Deaeration Current (A) (L/min) (MPa) (ppm) concentration Example 13 Done 18.0 3.0 0.4 3.3 0.976 Example 14 18.0 3.0 0.3 2.7 Example 15 18.0 3.0 0.2 2.3 Example 16 18.0 3.0 0.1 2.1 Example 17 Done 18.0 1.5 0.4 3.2 0.984 Example 18 18.0 1.5 0.3 2.9 Example 19 18.0 1.5 0.2 2.0 Example 20 18.0 1.5 0.1 1.5 Example 21 Done 6.0 1.5 0.4 1.7 1.000 Example 22 6.0 1.5 0.3 1.5 Example 23 6.0 1.5 0.2 1.3 Example 24 6.0 1.5 0.1 1.1

Examples 13 to 16 are those in which the hydrogen concentration was measured when the flow rate of the hydrogen-containing gas from the hydrogen supply source 2 was constant (18.0 A), the flow rate of the tap water from the liquid supply source 3 was constant (3.0 L/min), and the pressure of the gas/liquid mixture was varied from 0.1 to 0.4 MPa. The correlation coefficient between the pressure of the gas/liquid mixture and the hydrogen concentration is 0.976, which is very close to 1. Examples 17 to 20 are those in which the hydrogen concentration was measured when the flow rate of the tap water was 1.5 L/min as substitute for 3.0 L/min in Examples 13 to 16 and the pressure of the gas/liquid mixture was varied from 0.1 to 0.4 MPa. The correlation coefficient between the pressure of the gas/liquid mixture and the hydrogen concentration is 0.984, which is very close to 1. Examples 21 to 24 are those in which the hydrogen concentration was measured when the flow rate of the hydrogen-containing gas was 6.0 A as substitute for 18.0 A in Examples 17 to 20 and the pressure of the gas/liquid mixture was varied from 0.1 to 0.4 MPa. The correlation coefficient between the pressure of the gas/liquid mixture and the hydrogen concentration is 1.

As the above, also when the deaeration module 32 is provided, the correlation coefficient between the pressure of the gas/liquid mixture and the hydrogen concentration is 1 or very close to 1 at a given flow rate of the hydrogen-containing gas from the hydrogen supply source 2 and a given flow rate of the tap water from the liquid supply source 3. Accordingly, a relational expression thereamong is preliminarily obtained and stored in the ROM of the calculator 5. When the generator 1 for generating a hydrogen-containing liquid is actually used with a fixed value of the flow rate of the hydrogen-containing gas from the hydrogen supply source 2, that is, a fixed value of the current, the flow rate detected by the flow rate detector 52 and the water pressure detected by the water pressure detector 51 are read into the calculator 5, and the detected flow rate and the detected pressure are substituted into the relational expression to obtain the hydrogen concentration using the calculation program established in the ROM for obtaining the hydrogen concentration. This obtained hydrogen concentration is presented by the display 6 and the user can thus perceive the hydrogen concentration in the hydrogen-containing liquid from the supply port 45.

FIG. 3 is a block diagram illustrating still another embodiment of a generator 1 for generating a hydrogen-containing liquid according to the present invention. As illustrated in the figure, the generator 1 of the present embodiment uses an electrolyzed water generator as the hydrogen supply source 2. The electrolyzed water generator comprises an electrolyzer 23, a separating membrane 24, a pair of anode plate 25 and cathode plate 26 arranged to sandwich the separating membrane 24, a DC power source 27 configured to supply DC power to the anode plate 25 and the cathode plate 26, and a liquid 28 to be electrolyzed which is stored in the electrolyzer 23. The generator 1 is provided with a current detector 53 configured to detect a value of current flowing through the cathode plate 26 and its detection signal is read out by the calculator 5 at a predetermined time interval. Instead, the flow rate detector 52 provided at the flow rate regulating valve 44 is omitted. As compared with the generator 1 illustrated in FIG. 2, the generator 1 of the present embodiment is different in that the hydrogen supply tube 21 is provided with a fluid pressurization pump 29, but the fluid pressurization pump 29 may be omitted as necessary. Other features are the same as those illustrated in FIG. 1.

In the case of the embodiment illustrated in FIG. 3, the value of current flowing through the cathode plate 26 is variable while the opening degree of the flow rate regulating valve 44 is fixed. As described in the above Examples 1 to 24, the correlation coefficient between the pressure of the gas/liquid mixture and the hydrogen concentration is 1 or very close to 1 at a given flow rate of the hydrogen-containing gas from the hydrogen supply source 2 (a given value of current flowing through the cathode plate 26) and a given flow rate of the tap water from the liquid supply source 3. Accordingly, a relational expression thereamong is preliminarily obtained and stored in the ROM of the calculator 5. When the generator 1 for generating a hydrogen-containing liquid is actually used with a fixed value of the opening degree of the flow rate regulating valve 44, the current value detected by the current detector 53 and the water pressure detected by the water pressure detector 51 are read into the calculator 5, and the detected current value and the detected pressure are substituted into the relational expression to obtain the hydrogen concentration using the calculation program established in the ROM for obtaining the hydrogen concentration. This obtained hydrogen concentration is presented by the display 6 and the user can thus perceive the hydrogen concentration in the hydrogen-containing liquid from the supply port 45.

FIG. 4 is a block diagram illustrating yet another embodiment of a generator 1 for generating a hydrogen-containing liquid according to the present invention. The generator 1 of the present embodiment is different in that it has a plurality of (two in this example) hydrogen supply sources 2A and 2B for one liquid supply source 3. The hydrogen supply source 2A is to supply a hydrogen-containing gas and examples thereof include a hydrogen gas cylinder, hydrogen storing alloy, fuel reformer, and electrolyzed water generator. The hydrogen-containing gas supplied from the hydrogen supply source 2A is sent to a junction part 41A via a hydrogen supply tube 21A. The hydrogen supply tube 21A is provided with a check valve 22A, and the hydrogen-containing gas having passed through the check valve 22A does not return to the hydrogen supply source 2A. The hydrogen supply tube 21A may be provided with a fluid pressurization pump to regulate the supply pressure of the hydrogen-containing gas from the hydrogen supply source 2A to the junction part 41A. The hydrogen supply source 2B is also to supply a hydrogen-containing gas and examples thereof include a hydrogen gas cylinder, hydrogen storing alloy, fuel reformer, and electrolyzed water generator. The hydrogen-containing gas supplied from the hydrogen supply source 2B is sent to a junction part 41B via a hydrogen supply tube 21B. The hydrogen supply tube 21B is provided with a check valve 22B, and the hydrogen-containing gas having passed through the check valve 22B does not return to the hydrogen supply source 2B. The hydrogen supply tube 21B may be provided with a fluid pressurization pump to regulate the supply pressure of the hydrogen-containing gas from the hydrogen supply source 2B to the junction part 41B.

The liquid supply source 3 is to supply a liquid of the intended hydrogen-containing liquid, that is, a liquid to which hydrogen gas is to be dissolved. Examples of the liquid include water such as tap water, beverage, and medicinal liquid. The liquid supplied from the liquid supply source 3 is distributed at midstream of the liquid supply tube 31 and sent to each of the two junction parts 41A and 41B. The liquid supply tube 31 is provided with a deaeration module 32 and a vacuum pump 33. Turning on the vacuum pump 33 to operate the deaeration module 32 allows gases (mainly oxygen and other gases) to be removed from the liquid supplied from the liquid supply source 3. This operation can enhance the hydrogen concentration because the amount of contact between the liquid and the hydrogen gas increases in the passes from the junction parts 41A and 41B to dissolving units 4A and 4B which will be described later. In an alternative embodiment, the deaeration module 32 and the vacuum pump 33 may be omitted. The liquid supply tube 31 may be provided with one or more fluid pressurization pumps to regulate the supply pressure of the liquid from the liquid supply source 3 to each of the junction parts 41A and 41B. The liquid supply tube 31 may also be provided with a check valve so that the liquid from the liquid supply source 3 does not return thereto.

The junction part 41A is composed of a piping joint that connects between the hydrogen supply tube 21A and the liquid supply tube 31. The hydrogen-containing gas and liquid reaching the junction part 41A flow into a gas/liquid mixing pipe 42A and are sent under pressure to the downstream side by a fluid pressurization pump 43A provided at the gas/liquid mixing pipe 42A. The gas/liquid mixing pipe 42A is provided with a dissolving unit 4A at the downstream side from the fluid pressurization pump 43A. The gas/liquid mixing pipe 42A is also provided with a flow rate regulating valve 44A at the downstream side from the dissolving unit 4A.

The dissolving unit 4A is a cylindrical body having a larger inner diameter than that of the gas/liquid mixing pipe 42A and comprises a mixing body having fine pores, such as a membrane filter, which is provided inside the cylindrical body. When the gas/liquid mixture of the hydrogen-containing gas and the liquid passes through the fine pores of the membrane filter or the like, the hydrogen-containing gas becomes fine bubbles thereby to increase their surface area in contact with the liquid. Moreover, the hydrogen concentration increases because the hydrogen-containing gas in a form of fine bubbles and the liquid are pressurized in accordance with the pressurizing force by the fluid pressurization pump 43A and the opening degree of the flow rate regulating valve 44A. The hydrogen-containing liquid, which thus has a high concentration, is supplied from a supply port 45 to an intended site.

The junction part 41B is composed of a piping joint that connects between the hydrogen supply tube 21B and the liquid supply tube 31. The hydrogen-containing gas and liquid reaching the junction part 41B flow into a gas/liquid mixing pipe 42B and are sent under pressure to the downstream side by a fluid pressurization pump 43B provided at the gas/liquid mixing pipe 42B. The gas/liquid mixing pipe 42B is provided with a dissolving unit 4B at the downstream side from the fluid pressurization pump 43B. The gas/liquid mixing pipe 42B is also provided with a flow rate regulating valve 44B at the downstream side from the dissolving unit 4B.

The dissolving unit 4B is a cylindrical body having a larger inner diameter than that of the gas/liquid mixing pipe 42B and comprises a mixing body having fine pores, such as a membrane filter, which is provided inside the cylindrical body. When the gas/liquid mixture of the hydrogen-containing gas and the liquid passes through the fine pores of the membrane filter or the like, the hydrogen-containing gas becomes fine bubbles thereby to increase their surface area in contact with the liquid. Moreover, the hydrogen concentration increases because the hydrogen-containing gas in a form of fine bubbles and the liquid are pressurized in accordance with the pressurizing force by the fluid pressurization pump 43B and the opening degree of the flow rate regulating valve 44B. The hydrogen-containing liquid, which thus has a high concentration, is supplied from a supply port 45 to an intended site.

The generator 1 for generating a hydrogen-containing liquid according to the present embodiment comprises, in addition to the above-described configuration, water pressure detectors 51A and 51B each configured to detect the water pressure of the hydrogen-containing liquid, flow rate detectors 52A and 52B each configured to detect the flow rate of the hydrogen-containing liquid, a calculator 5, and a display 6.

The water pressure detector 51A is provided on the gas/liquid mixing pipe 42A between the fluid pressurization pump 43A and the dissolving unit 4A and detects the water pressure of the hydrogen-containing liquid (gas/liquid mixture of the hydrogen-containing gas and the liquid) which is pressurized by the fluid pressurization pump 43A. The detection signal from the water pressure detector 51A is read out by the calculator 5 at a predetermined time interval. In an alternative embodiment, the water pressure detector 51A may be provided on the gas/liquid mixing pipe 42A between the dissolving unit 4A and the flow rate regulating valve 44A. The water pressure detector 51B is provided on the gas/liquid mixing pipe 42B between the fluid pressurization pump 43B and the dissolving unit 4B and detects the water pressure of the hydrogen-containing liquid (gas/liquid mixture of the hydrogen-containing gas and the liquid) which is pressurized by the fluid pressurization pump 43B. The detection signal from the water pressure detector 51B is read out by the calculator 5 at a predetermined time interval. In an alternative embodiment, the water pressure detector 51B may be provided on the gas/liquid mixing pipe 42B between the dissolving unit 4B and the flow rate regulating valve 44B.

The flow rate detector 52A detects the opening degree of the flow rate regulating valve 44A to detect the flow rate of the hydrogen-containing liquid. The detection signal from the flow rate detector 52A is read out by the calculator 5 at a predetermined time interval. In an alternative embodiment, the flow rate detector 52A may be provided on the gas/liquid mixing pipe 42A between the flow rate regulating valve 44A and the supply port 45. The flow rate detector 52B detects the opening degree of the flow rate regulating valve 44B to detect the flow rate of the hydrogen-containing liquid. The detection signal from the flow rate detector 52B is read out by the calculator 5 at a predetermined time interval. In an alternative embodiment, the flow rate detector 52B may be provided on the gas/liquid mixing pipe 42B between the flow rate regulating valve 44B and the supply port 45.

The calculator 5 is composed of a microcomputer that includes a CPU, ROM, and RAM. The ROM also functions as a storage that stores preliminarily-obtained relational information among the flow rate, water pressure, and hydrogen concentration of the hydrogen-containing liquid passing through each of the dissolving units 4A and 4B. In the ROM, a calculation program is established to obtain the hydrogen concentration in actual use on the basis of the detected flow rate and water pressure and the relational information.

The display 6 is to present the hydrogen concentration obtained by the calculator 5. Examples of the display 6 include indicators, such as a seven-segment digital indicator, with which the concentration can be visually recognized and those, such as a speaker, with which the concentration can be audibly perceived.

Also in the generator 1 for generating a hydrogen-containing liquid of the present embodiment configured as the above, the correlation coefficient between the pressure of the gas/liquid mixture and the hydrogen concentration is very close to 1 at a given flow rate of the hydrogen-containing gas from each of the hydrogen supply sources 2A and 2B and a given flow rate of the tap water from the liquid supply source 3. Accordingly, a relational expression thereamong is preliminarily obtained and stored in the ROM of the calculator 5.

When the generator 1 for generating a hydrogen-containing liquid is actually used with a fixed value of the flow rate of the hydrogen-containing gas from each of the hydrogen supply sources 2A and 2B, that is, a fixed value of each current flowing through the cathode plate, the flow rate detected by each of the flow rate detectors 52A and 52B and the water pressure detected by each of the water pressure detectors 51A and 51B are read into the calculator 5, and the detected flow rate and the detected pressure are substituted into the relational expression to obtain the hydrogen concentration using the calculation program established in the ROM for obtaining the hydrogen concentration. This obtained hydrogen concentration is presented by the display 6 and the user can thus perceive the hydrogen concentration in the hydrogen-containing liquid from the supply port 45.

Instead, as in the embodiment illustrated in FIG. 3, when the generator 1 for generating a hydrogen-containing liquid is actually used with a fixed value of the opening degree of each of the flow rate regulating valves 44A and 44B, the current value detected by each of current detectors (53A and 53B, not illustrated) and the water pressure detected by each of the water pressure detectors 51A and 51B are read into the calculator 5, and the detected current value and the detected pressure are substituted into the relational expression to obtain the hydrogen concentration using the calculation program established in the ROM for obtaining the hydrogen concentration. This obtained hydrogen concentration is presented by the display 6 and the user can thus perceive the hydrogen concentration in the hydrogen-containing liquid from the supply port 45.

DESCRIPTION OF REFERENCE NUMERALS

-   1 Generator for a hydrogen-containing liquid -   2, 2A, 2B Hydrogen supply source -   21, 21A, 21B Hydrogen supply tube -   22, 22A, 22B Check valve -   23 Electrolyzer -   24 Separating membrane -   25 Anode plate -   26 Cathode plate -   27 DC power source -   28 Liquid to be electrolyzed -   29 Fluid pressurization pump -   3 Liquid supply source -   31 Liquid supply tube -   32 Deaeration module -   33 Vacuum pump -   4, 4A, 4B Dissolving unit -   41, 41A, 41B Junction part -   42, 42A, 42B Gas/liquid mixing pipe -   43, 43A, 43B Fluid pressurization pump -   44, 44A, 44B Flow rate regulating valve -   45 Supply port for hydrogen-containing liquid -   5 Calculator (calculator, storage) -   51, 51A, 51B Water pressure detector -   52, 52A, 52B Flow rate detector -   53 Current detector (Electric quantity detector) -   6 Display (Presentation unit) 

What is claimed is:
 1. A method of obtaining a hydrogen concentration in a hydrogen-containing liquid, comprising: continuously generating the hydrogen-containing liquid by dissolving a hydrogen-containing gas in a continuously flowing liquid; preliminarily obtaining a relationship among a flow rate and water pressure of the hydrogen-containing liquid and the hydrogen concentration; detecting the flow rate and water pressure of the hydrogen-containing liquid; and obtaining the hydrogen concentration on a basis of the detected flow rate and water pressure and the relationship.
 2. A method of obtaining a hydrogen concentration in a hydrogen-containing liquid, comprising: continuously generating the hydrogen-containing liquid by dissolving a hydrogen-containing gas in a continuously flowing liquid of which a flow rate is variable, the hydrogen-containing gas being generated by electrolysis of water; preliminarily obtaining a relationship among an electric quantity during the electrolysis, a water pressure of the hydrogen-containing liquid, and the hydrogen concentration; detecting the electric quantity during the electrolysis and the water pressure of the hydrogen-containing liquid when the flow rate of the hydrogen-containing liquid is a fixed value; and obtaining the hydrogen concentration on a basis of the detected electric quantity and water pressure and the relationship.
 3. A method of obtaining a hydrogen concentration in a hydrogen-containing liquid, comprising: continuously generating the hydrogen-containing liquid by dissolving a hydrogen-containing gas in a continuously flowing liquid of which a flow rate is variable, the hydrogen-containing gas being generated by electrolysis of water; preliminarily obtaining a relationship among an electric quantity during the electrolysis, a water pressure of the hydrogen-containing liquid, a flow rate of the hydrogen-containing liquid, and the hydrogen concentration; detecting the electric quantity during the electrolysis, the water pressure of the hydrogen-containing liquid, and the flow rate of the hydrogen-containing liquid; and obtaining the hydrogen concentration on a basis of the detected electric quantity, water pressure, and flow rate and the relationship.
 4. A generator for a hydrogen-containing liquid, comprising: a hydrogen supply source configured to continuously supply a hydrogen-containing gas; a liquid supply source configured to continuously supply a liquid; a dissolving unit configured to dissolve the hydrogen-containing gas in the liquid to continuously generate the hydrogen-containing liquid; a memory configured to store preliminarily-obtained relational information among a flow rate, water pressure, and hydrogen concentration of the hydrogen-containing liquid passing through the dissolving unit; a flow rate detector configured to detect the flow rate of the hydrogen-containing liquid; a water pressure detector configured to detect the water pressure of the hydrogen-containing liquid; and a calculator configured to obtain the hydrogen concentration on a basis of the detected flow rate and water pressure and the relational information.
 5. A generator for a hydrogen-containing liquid, comprising: a hydrogen supply source configured to continuously supply a hydrogen-containing gas by electrolysis of water; a liquid supply source configured to continuously supply a liquid of which a flow rate is variable; a dissolving unit configured to dissolve the hydrogen-containing gas in the liquid to continuously generate the hydrogen-containing liquid; a memory configured to store preliminarily-obtained relational information among an electric quantity during the electrolysis, a water pressure of the hydrogen-containing liquid passing through the dissolving unit, and a hydrogen concentration of the hydrogen-containing liquid passing through the dissolving unit; an electric quantity detector configured to detect the electric quantity during the electrolysis when the flow rate of the hydrogen-containing liquid is a fixed value; a water pressure detector configured to detect the water pressure of the hydrogen-containing liquid when the flow rate of the hydrogen-containing liquid is a fixed value; and a calculator configured to obtain the hydrogen concentration on a basis of the detected electric quantity and water pressure and the relational information.
 6. A generator for a hydrogen-containing liquid, comprising: a hydrogen supply source configured to continuously supply a hydrogen-containing gas by electrolysis of water; a liquid supply source configured to continuously supply a liquid; a dissolving unit configured to dissolve the hydrogen-containing gas in the liquid to continuously generate the hydrogen-containing liquid; a memory configured to store preliminarily-obtained relational information among an electric quantity during the electrolysis, a water pressure of the hydrogen-containing liquid passing through the dissolving unit, a flow rate of the hydrogen-containing liquid passing through the dissolving unit, and a hydrogen concentration of the hydrogen-containing liquid passing through the dissolving unit; an electric quantity detector configured to detect the electric quantity during the electrolysis; a water pressure detector configured to detect the water pressure of the hydrogen-containing liquid; a flow rate detector configured to detect the flow rate of the hydrogen-containing liquid; and a calculator configured to obtain the hydrogen concentration on a basis of the detected electric quantity, water pressure, and flow rate and the relational information.
 7. The generator for a hydrogen-containing liquid according to claim 4, further comprising a presentation unit configured to present the hydrogen concentration obtained by the calculator.
 8. The generator for a hydrogen-containing liquid according to claim 5, further comprising a presentation unit configured to present the hydrogen concentration obtained by the calculator.
 9. The generator for a hydrogen-containing liquid according to claim 6, further comprising a presentation unit configured to present the hydrogen concentration obtained by the calculator. 